I connected my SP4 to an LCD monitor through a Mini DisplayPort to DVI adapter. I then used Windows-P shortcut to display on the monitor only. The screen looked blurry; text was hard to read and when I used the Snipping Tool to take a screenshot, the resulting image was not what was selected with my mouse. I rebooted the SP4 with the Mini DP-DVI adapter plugged in hoping this would resolve the problem but it did not. When I right-clicked the desktop and selected display settings, "change the size of text, apps, and other items" was grayed out and I also cannot change screen resolution in advanced display settings, as it's also grayed out.
Next, I went into the device manager and checked for updates for the Intel HD Graphics 520 display adapter but I have the latest version installed (20.19.15.4463). I went to the Microsoft site and downloaded the latest driver pack and to try updating the driver manually. I noticed that when I uninstalled the Intel display adapter, the issue was resolved; my monitor display was perfect and I was able to change text size and resolution. I updated the driver and rebooted which resulted in a blurry display again.
Currently, I'm working around this issue by uninstalling the display adapter from the device manager and not rebooting. Any ideas for a permanent solution?

Instead of Windows Key-P which is to project to another display have you tried Settings/System/Display? You can choose to extend, duplicate or use monitor 2 only. I don't know if this is the same thing as Project to another display.

Instead of Windows Key-P which is to project to another display have you tried Settings/System/Display? You can choose to extend, duplicate or use monitor 2 only. I don't know if this is the same thing as Project to another display.